In the crystal structure of the title compound, C(22)H(17)N(3)O, the oxazine ring has a half-chair conformation. The dihedral angles between the best least-squares plane through the pyridine rings and the planar part (O-C-C-C-N) of the oxazine ring are 72.14 (6) and 35.44 (7)°, the smaller angle involving the pyridine ring adjacent to the oxazine O atom. The mol-ecule has two stereogenic centers at the oxazine carbons, RS and SR. The crystal packing reveals that symmetry-related mol-ecules are linked by inter-molecular N-H⋯N hydrogen bonds to form chains parallel to the b axis.